Inclusion criteria for adults with ID will include:

• ages 18 and older with a prior clinical diagnosis of ID, confirmed by scores < 70 and + 90% on the Leiter-3 International Performance Scales and/or an adaptive behavior measure using the Vineland Adaptive Behavior Scales,
• Medical clearance to participate in moderate-to-vigorous physical activity as determined by the American College of Sports Medicine (ACSM) preparticipation algorithm,
• Adult does not show clinically elevated symptoms of Alzheimer's Disease (AD)/ Alzheimer's Disease and Related Dementias (ADRD) as indicated by a score of < 20 on the Dementia Screening Questionnaire for Individuals with Intellectual Disabilities.
• One caregiver/guardian is able and willing to participate.
• must tolerate at least 8 hours of daily wear-time of Actigraph device during initial assessment period (4 of 7 days),
• must average 20 minutes or less of moderate to vigorous physical activity (MVPA) minutes per day (140 MVPA minutes or less across 7-day period measured during the initial assessment period, and
• must reside in North Carolina or Arkansas.

Exclusion Criteria for adults with ID:

• Diagnosis of AD, dementia, or related disorders. Participants will not be excluded based on gender, race, or ethnicity. There will be no upper age limit due to the heterogeneity of onset of AD/ADRD in individuals with ID.

Inclusion criteria for coach will include:

• access to the internet and a mobile device,
• has weekly contact with the adult participant with ID,
• can converse and read in English to comprehend intervention materials and website content, and
• must reside in North Carolina or Arkansas

Inclusion criteria for caregiver will include:

• ability to converse and read in English to comprehend and answer interview questions, (2) must care for an adult with ID who is willing to participate in the study,
• must reside in North Carolina or Arkansas, and
• must attend all study visits with adult with ID.